greetings, I have had quite a saga helping a friend with his 97 Tacoma 4x4 with a 3.4L 5vz-FE(while sadly my FJ-80 waits its turn for garage time).
Here's the story, he randomly had steam coming out the exhaust one day and thankfully had the sense to get a tow, he said it never got hot and I believe him.
I took a look, saw the steam out the tailpipe, mayonnaise for oil and thought it was a classic blown head gasket. I knew these motors are not the easiest to work on but i'm a glutton for punishment and wanted to help a friend out.
after trying to isolate which cylinder was low compression I pulled the head off, didn't really see a smoking gun, so I went ahead an pulled them both off.
I cleaned everything up, bought an awesome straight edge, tested the heads and block per factory service manual and found a spot on the block that seemed about .005-.007 out, and looked quite rusty.
it was close to the FSM tolerances and I really didn't want to strip the block so I went ahead and threw new Fel Pro head gaskets in and put it back together.
no Luck.... still had steam ut the exhaust and mayo for oil... a good waste of Mobile one if you ask me.
so next I figured I had to bite the bullet and go to the machine shop with block and heads.... though to my credit, I did try to talk my friend into buying a rebuilt long block at this point, since I knew how much work was ahead of me.
I should have tried harder, but secretly I wanted to rebuild this motor. call me foolish, I like challenges I guess. or at least I did at the time...
I yanked the motor, mounted it on a borrowed engine stand and got it down to bare block and heads.
I found a machine shop that was recommended by a few local mechanics and left it. it turned out to be quite an ordeal, and the shop took months before they even got them in the tank to get clean, but eventually I harassed them enough to get the work done. they didn't find any cracks, and resurfaced the heads and block at the gasket surface, gave a nice cylinder hone while they were at it. they said the valve seats looked pretty good (this motor only has about 120k on it).
I bought a mix of parts to rebuild it, using as much OEM as my friend could afford, including main bearings timing belt, oil and water pumps. it took a while, but it all went together smoothly and I was extremely anal about all the tolerances and torque. (Thanks to the mud forum for FSM links!)
in hindsight this may have been a mistake, but I did not use OEM head gaskets, I used the ones that came in my engine rebuild kit, which was made by Evergreen. seemed a shame to throw them away but now im doubting that decision.
also possibly a mistake: my friend who is an experience BMW mechanic recommended I spray the gasket down with copper spray before reassembling.
once it was back together and fluids filled, I did the full routine to prime the oil pump, by removing the EFI fuse and cranking for intervals, then letting the starter cool down. eventually I had oil pressure and it was the moment of glory or disappointment. the latter it turns out.
I started it up and after a few minutes, sure enough... steam coming out the exhaust again. I checked the oil and still no mayonnaise, so decided to let it run in case it was just condensation in the exhaust, but sure enough soon a good sized cloud of mist was coming out the tail pipe and eventually i shut it down. I swore a bit. also, the oil was getting a little bit discolored but still mostly clear.
I tested the compression and one cylinder was 12 psi lower than the others
I went ahead and pulled the heads again, and couldn't see any particular failure at the head gasket, nor could I see anywhere that the copper spray didn't seem to bond to the block or heads. there was possibly evidence of moisture in one cylinder, but it was hard to tell. At this point I was hoping that we missed a crack in the heads, so i stripped them and took them to a different machine shop. they pressure tested them and they are both fine, and have nice flat surfaces for the gasket.
So this is where I am at, the heads are still off and Im trying to decide if I try OEM or other high quality head gaskets and hope we didn't miss a crack in the block. I really don't see how we could have missed one, especially with the cylinder hone, I gambled that a cracked block was the least likely scenario compared to what I have already done. At this point my friend is finally ready to pay for a rebuilt short block if necessary... yotaparts.com has one for $1600 plus $169 shipping, i'm really torn what to do, and need to get this thing out of my garage.
Advice please, and thank you!!!
Here's the story, he randomly had steam coming out the exhaust one day and thankfully had the sense to get a tow, he said it never got hot and I believe him.
I took a look, saw the steam out the tailpipe, mayonnaise for oil and thought it was a classic blown head gasket. I knew these motors are not the easiest to work on but i'm a glutton for punishment and wanted to help a friend out.
after trying to isolate which cylinder was low compression I pulled the head off, didn't really see a smoking gun, so I went ahead an pulled them both off.
I cleaned everything up, bought an awesome straight edge, tested the heads and block per factory service manual and found a spot on the block that seemed about .005-.007 out, and looked quite rusty.
it was close to the FSM tolerances and I really didn't want to strip the block so I went ahead and threw new Fel Pro head gaskets in and put it back together.
no Luck.... still had steam ut the exhaust and mayo for oil... a good waste of Mobile one if you ask me.
so next I figured I had to bite the bullet and go to the machine shop with block and heads.... though to my credit, I did try to talk my friend into buying a rebuilt long block at this point, since I knew how much work was ahead of me.
I should have tried harder, but secretly I wanted to rebuild this motor. call me foolish, I like challenges I guess. or at least I did at the time...
I yanked the motor, mounted it on a borrowed engine stand and got it down to bare block and heads.
I found a machine shop that was recommended by a few local mechanics and left it. it turned out to be quite an ordeal, and the shop took months before they even got them in the tank to get clean, but eventually I harassed them enough to get the work done. they didn't find any cracks, and resurfaced the heads and block at the gasket surface, gave a nice cylinder hone while they were at it. they said the valve seats looked pretty good (this motor only has about 120k on it).
I bought a mix of parts to rebuild it, using as much OEM as my friend could afford, including main bearings timing belt, oil and water pumps. it took a while, but it all went together smoothly and I was extremely anal about all the tolerances and torque. (Thanks to the mud forum for FSM links!)
in hindsight this may have been a mistake, but I did not use OEM head gaskets, I used the ones that came in my engine rebuild kit, which was made by Evergreen. seemed a shame to throw them away but now im doubting that decision.
also possibly a mistake: my friend who is an experience BMW mechanic recommended I spray the gasket down with copper spray before reassembling.
once it was back together and fluids filled, I did the full routine to prime the oil pump, by removing the EFI fuse and cranking for intervals, then letting the starter cool down. eventually I had oil pressure and it was the moment of glory or disappointment. the latter it turns out.
I started it up and after a few minutes, sure enough... steam coming out the exhaust again. I checked the oil and still no mayonnaise, so decided to let it run in case it was just condensation in the exhaust, but sure enough soon a good sized cloud of mist was coming out the tail pipe and eventually i shut it down. I swore a bit. also, the oil was getting a little bit discolored but still mostly clear.
I tested the compression and one cylinder was 12 psi lower than the others
I went ahead and pulled the heads again, and couldn't see any particular failure at the head gasket, nor could I see anywhere that the copper spray didn't seem to bond to the block or heads. there was possibly evidence of moisture in one cylinder, but it was hard to tell. At this point I was hoping that we missed a crack in the heads, so i stripped them and took them to a different machine shop. they pressure tested them and they are both fine, and have nice flat surfaces for the gasket.
So this is where I am at, the heads are still off and Im trying to decide if I try OEM or other high quality head gaskets and hope we didn't miss a crack in the block. I really don't see how we could have missed one, especially with the cylinder hone, I gambled that a cracked block was the least likely scenario compared to what I have already done. At this point my friend is finally ready to pay for a rebuilt short block if necessary... yotaparts.com has one for $1600 plus $169 shipping, i'm really torn what to do, and need to get this thing out of my garage.
Advice please, and thank you!!!
